Translucent Oak Galls

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One of my all-time favorite plant galls is the appropriately named Translucent Oak Gall.  The galls are produced by the gall-wasp, Amphibolips nubilipennis (family Cynipidae).  They arise from a leaf vein on the lower leaf surface and measure around 1/2 - 3/4" in diameter.  Their shape and color causes them to strongly resemble tiny, pink balloons or pink grapes hanging beneath the leaves of red, scarlet, and black oaks. 

Translucent Oak Gall w-exit hole

Slicing the succulent gall open will reveal a single wasp larva housed in a chamber in the center of the gall.  The larval chamber appears to be resting on a white pedestal.  The gall will have a single, round hole through the surface of the gall that leads to a tunnel to the larval chamber if the immature wasp has completed its development exited its gall-home.  As with most oak galls, these galls can be appreciated free of fear for the health of the host tree

Translucent Oak Gall cut open